CI: Add generic test file for publish job (#79)

#### Problem

The publish job failed because it uses a `test.mjs` file which isn't in
the repo.

#### Summary of changes

Add the file.

Author: joncinque

scripts/rust/test.mjs

@@ -0,0 +1,8 @@
+#!/usr/bin/env zx
+import 'zx/globals';
+import { cliArguments, workingDirectory } from '../utils.mjs';
+
+const [folder, ...args] = cliArguments();
+const sbfOutDir = path.join(workingDirectory, 'target', 'deploy');
+const manifestPath = path.join(workingDirectory, folder, 'Cargo.toml');
+await $`RUST_LOG=error SBF_OUT_DIR=${sbfOutDir} cargo test --manifest-path ${manifestPath} ${args}`;